The electron acceptor in the light-dependent reaction series of photosynthesis is NADP. Energy from the sun causes chlorophyll to lose an electron. This electron travels through a cascade of reactions to ultimately convert a molecule of NADP to NADPH. This sets up a proton gradient across the chloroplast membrane that drives the conversion of ADP to ATP. NADP stands for nicotinamide adenine dinucleotide phosphate. It consists of two ribose sugar molecules linked together by a diphosphate chain. One ribose has an adenine group and the other the nicotinamide group. The nicotinamide group is positively charged in NADP and readily accepts an electron and proton to add a hydrogen to the aromatic ring. The structure of NADP is shown in the second link below.